Breathing apparatus of the rebreather type



April 9, 1957 Filed Aug. 14, 1953 A. 5. BROWN 2,783,001

BREATHING APPARATUS OF THE REBREATHER TYPE 3 Sheets-Sheet l 5 INVENTOR ARTHUR 5. BROWN ATTOR NEY April 9, 1957 A. 5. BROWN BREATHING APPARATUS OF THE REBREATHER TYPE 5 Sheets-Sheet 2 Filed Aug. 14, 1955 IN VENTOR ARTHUR 5 Bnow/v aA/fi JMMT ATTORNEY April 1957 A. 5. BROWN BREATHING APPARATUS OF THE REBREATHER TYPE 5 Shets-Sheet 5 Filed Aug. 14, 1953 1N VENTOR ARTHUR 5. BROWN BY /Z:Z%

ATTORNEYS Unit d Stat s P t n 2,788,001 BREATHING APPARATUS 9F THE REBREATHER TYP Arthur S. Brown, Milford, Conm, assignor, by direct and mesne assignments, to The Cycle Flo Company, Milford, Conn., a corporation of Connecticut Application August 14, 1953, Serial No. 374,182 9 Claims. (Cl. 128-142) This invention relates to breathing apparatus and relates more particularly to breathing apparatus of'the rebreather type. I

One object of the invention is to provide an apparatus of the type described comprising a receptacle for exhaled gas or gases to be rebreathed, and also comprising physical means tending to exclude the exhaled gas from the gas inhaled during the first period of inhalation so that the latter may be maintained in a substantially pure state.

Other objects of the invention will be apparent hereinafter from the following detailed description of twoforms of the invention. i

In the drawings 2,

Fig. 1 is an elevational view illustrating a breathing apparatus of the rebreather type embodying the invention; Fig. 2 is a similar view but illustrating the apparatus partially in section;

Fig. 3 is a sectional view taken on line 3- 3 of Fig. 2, illustrating the relationship of the apparatus to the face of the user;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 2;

Fig. 5 is an elevational view of a breathing apparatus of the type described illustrating a modified form of the invention, the apparatus being shown partially in section; and

' Fig. 6 isa sectional view taken on line 6 6 of Fig. 5.

In the form of the invention illustrated in Figs. 1 through 4 of the drawings, theapparatus comprises, in general, an oro-nasal face; piece and a body depending from 'the face piece, the face'piece being, indicated at 19 and the body being indicated at 11. The face piece It) may be of conventional form and is illustrated in Fig. 3 in; the operative position thereof. Suitable means, not shown, may "be provided'on' the face piece 10 to attach the latterto thehead of the user in the operative position thereof. The face piece 10 is provided with a depending tubular portion 19? and is provided with, a check valve12 adjacent the tubular portion 10*. The check valve 12 is an exhaust va'lve and may be of the spring-loaded type. However, I prefer to employ agvalvestructure of the type described in the Young p'atent, No 2,225 ,395', issued December 17, 1940, and comprising a tubularlniember 12 suitably secured to thefacepiece and providing a valve seat, the tubular, member 12 being provided with a bridge 12 having an orifice therein, and'alsov comprising a closing disk 125 611? rubber material having an. elastic stem portion received in". the orifice formed in the bridge 12 and tensioned' thereby. Entering the body 11 is a conduit 13' for a gas suchfa's. oxygen, for example, supplied from a source of oxygen under pressure, which sourceis not Shown A tubular member 14 is vertically disposed in the body 11 and has an open upper end incommunication with the tubular portion 10 of the face piece. The tubular n ember 141may be formed conveniently of rubber and communicates with, the gas conduit 13, the terminal of the latter being disposed at the lower end of the member 14, asilltistrated inFigl' 2 'ofthe drawings, for example. The

2,788,001 Patented Apr. 9 1957- 2 terminal of the gas conduit 13 may be secured to the tubular member 14 by an annular member 14 receiving the terminal of the gas conduit 13 and being suitably secured thereto, the annular member 14*? being snugly received in the lower end of the tubular member 14 and being secured thereto as by a clamp 14 embracing the tubular member 14 at the lower end thereof. The tubular member 14 is closed by a check valve or ox-ygen-inlet valve 15 disposed intermediate the ends thereof. The valve 15 may be of the same type as the valve 12. The arrangement is such that the valve 15 may be opened by suction to admit oxygen to the upper end portion of the tubular member 14 from thelower end of the latter. Intermediate the oxygen-inlet valve 15 and the upper end of the tubular' member 14, the member 14 is provided with a checkvalve or exhaust valve 16for exhaled gases. The exhaust valve 16 may be of the same type as the valve 12 and opens through the side wall structure of the tubular member 14' into a receptacle 17. The valve 12 is spring biased toward the closed position thereof more strongly than the valve 16. Adjacent the annular member 14, the tubular member 14 is provided with a check valve or inlet valve 16 which may be similar to the valve 15, the valve 16 being a suction valve, and being interposed between the receptacle 17 and the tubular member 14 and opening into the latter through the side wall structure thereof.

' The receptacle 17'may be constituted by a flexible bag for exhaled gases to be rebreathed, the bag 17 being dis-Q posed over the tubular member 14 and forming the outer part of the body ll'of the apparatus. The bag 17, which may be formed conveniently of rubber, has the upper end thereof disposed adjacent the upper end of the tubular member 14, and the bag 17 and the tubular member 14 may be clamped to the depending portion 16 of the face piece by a clamp 19, as illustrated in Fig. l, for example. The lower end of the bag 17, which bag is commonly known as a rebreather bag, is spaced a distance below the lower end of the tubular member 14 and is penetrated by the oxygen conduit 13. A clamp 20 may be provided to clamp the lower end of the rebreather bag 17 to the oxygen conduit 13, as illustrated in Fig, 1, for example. The rebreather bag 17' may be provided with reentrant side pleats 21 to facilitate expansion and collapse of the bag 17, the cross-sectional form of the bag 17, when partially inflated, being illustrated in Fig. 4. The substantially fully inflated state of the rebreather bag 17 is illustrated in'broken lines in Fig. 3 of the drawings. As illustrated in Fig. 2 of the drawings, for example, the depending portion 10 of the face piece may be strengthened by a metal ferrule 10 inserted therein.

In operation, oxygen under pressure may flow con stantly through the conduit 13 to the oxygen receptacle formed by the extension of the tubular member 14 below the check valve 15. The arrangement is such that oxygen is first collected in the tubular member 1 5 adjacent the lower end thereof, and then, as the quantity of oxygen collected increases, moves upwardly in the tubular member 14 displacing any other gas therein. The pressure of the gas or gases in the tubular member 14 may be sufiicient to open the valve 15, and the valve 16 if the bag 17-is not fully inflated, and may be SUll'lClCl'li to open the valve 12, thereby substantially filling the tubular member 14 and the face piece 10 with oxygen and tending to purge the member 14 and the face piece 10 of any other gas. During the first period of inhalation by the user, the gas inhaled is the relatively pure oxygen previously collected in the face piece and the portion of the tubular member 14 above the check valve 15. Then, if the check valve 15 is not in open position, the suction of inhalation opens the valve 15 and the relatively pure oxygen in the lower portion of the tubular member 14 is'inhaled. The relatively pure oxygen thus inhaled penetrates to the lower respiratory levels of the user's lungs and permits a chemical reaction in which a portion of the oxygen is. absorbed by the body, the portion of the oxygen absorbed by the body being replaced by an approximately equal amount of carbon dioxide and water vapor. During the immediately following and final period of inhalation, the gas exhaled .by the next preceding exhalation and previously stored in the rebreather bag 17 passes through the suction valves 16 and 15 provided in the tubular member 14 and is inhaled by the user. It will be understood that exhaled gas in the rebreather bag 17 is admitted to the lower end of the tubular member 14 and passes upwardly therein following the oxygen previously collected in the tubular member 14. The gas inhaled during the last-mentioned portion of the inhalation is commonly known as dead air for it does not act chemically with the body but serves merely as fill for the nasal, oral, sinus and upper bronchial cavities. Thus it will be understood that the aforementioned first period is the critical period of inhalation. During the first period of exhalation, the gas which is discharged is said dead air, which is exhausted through the valve 16 into the rebreather bag 17, filling the latter. The gas which is exhaled during the immediately following final period of exhalation, and which is heavily contaminated with carbon dioxide and water vapor, is exhausted to the atmosphere through the check valve 12, the pressure in the face piece 10 when the rebreather bag is full being sufiicient to open the check valve 12. The preferential oxygen-supply cycle described above is then repeated by the breathing of the user, and it may be noted in this connection that the check valve 15 is always closed by the force of exhalation during the exhalation period of the breathing cycle.

In the form of the invention illustrated in Figs. 5 and 6 of the drawings, a tubular member 22 of smaller linear dimensions than the tubular member 14, previously described, is provided and may be secured to the face piece in the manner in which the tubular member 14 is secured to the face piece 10, as described above. Adjacent the lower end of the tubular member 22, the mem ber 22 is closed by a check valve or oxygen-inlet valve 23 similar to the valve 15 previously described. The side-wall structure of the tubular member 22 is provided with a check valve or inlet valve 24 for exhaled gases, the valve 24 opening into the tubular member 22 and permitting entry therein of exhaled gases from the re-v breather bag. The valve 24 may be similar to the valve 23 and may be opened by suction. As illustrated in Fig. 5 of the drawings, for example, the valve 24 is disposed above the valve 23. Diametrically opposite the valve 24, the tubular member 22 is provided with a check valve or outlet valve 25 preferably similar to the valve 16, previously described, for exhausting exhaled gases into the rebreather bag from the tubular member 22.

A supplemental receptacle or flexible bag 26, conveniently formed of rubber and of the same type but considerably smaller than the rebreather, is disposed in the rebreather bag, which may be identical to the rebreather bag 17 previously described, the supplemental bag 26 being in communication with the tubular member 22 and forming a lower extension thereof, the upper end of the supplemental bag 26 being clamped to the tubular member 22 by a clamp 27, as illustrated in Fig. 6 of the drawings, for example. An oxygen-supply conduit 28 is provided communicating with the supplemental bag 26 and being clamped to the bag 26 by a clamp 29, as illustrated in Fig. 5 of the drawings, for example. The rebreather bag extends a short distance below the supplemental bag 26 and is penetrated by the oxygen-supply conduit 28, the rebreather bag being secured to the conduit 28 by a clamp 29 as illustrated in Fig. 6 of the drawings, for example. In the form of the invention illustrated in Figs. 5 and 6 of the drawings, the face piece may be identical to the face piece 10, previously described. The

. 4 valve 12 is spring-biased toward the closed position thereof more strongly than the valve 25, and the valve 24 is spring-biased toward the closed position thereof more strongly than the valve 23.

The operation of the apparatus illustrated in Figs. 5 and 6 of the drawings is in some respects similar to the operation of the apparatus disclosed in Figs. 1 through 4 of the drawings. In both forms of the invention, oxygen supplied from the oxygen conduit is collected in an oxygen receptacle, tending to exclude exhaled gases in the rebreather bag, and which is emptied upon inhalation prior to inhalation of gases previously exhaled and confined in the rebreather bag. However, in the apparatus illustrated in Figs. 5 and 6 of the drawings, the inlet valve 24 for exhaled gases is disposed intermediate the oxygen-inlet valve 23 and the face piece 10, and the arrangement is such that exhaled gas, physically separated from the contents of the oxygen bag 26, passes on inhalation not through the oxygen receptacle 26 and the valve 23, but through the valve 24.

In accordance with the invention, an apparatus is provided which may constitute a closed breathing system, i. e., a system in which no part of the gas delivered to the user is supplied from the ambient atmosphere. It will be appreciated that in a closed system for uses other than anesthetization, the quantity of carbon dioxide in the system must be kept to a minimum to avoid the danger of rendering the user ill or uncomfortable. Heretofore attempts have been made to reduce carbon dioxide contamination by use of chemicals in breathing apparatus. One important advantage of a breathing apparatus embodying the invention resides in the provision of physical means tending to exclude exhaled gas from the gas inhaled during the first period of inhalation and maintaining the latter substantially free from carbon dioxide.

In accordance with the invention, the consumption of oxygen in the operation of the apparatus is maintained at extraordinarily low levels owing to the provision of means for supplying relatively pure oxygen to the user only during the first period of inhalation. Heretofore, it has been the practice to provide oxygen in a rebreather system only in mixtures including exhaled gases. The quantity of oxygen required to enrich exhaled gases snfiiciently for continued breathing is greatly in excess of the amount of oxygen required by the user of an apparatus embodying the invention. In this connection, it may be noted that the user of a breathing'apparatus embodying the invention may easily carry on his person a supply of oxygen which may last for a period of thirty minutes or for longer periods, the breathing apparatus and a thirty-minute oxygen supply weighing approximately ten pounds only. It will be understood that the breathing apparatus of the invention may be used for a number of purposes. For example, the apparatus may be used in firefighting and in industrial work.

While two forms of the invention have been illustrated in the drawings and described above, it will be understood that the invention may take other forms within the scope of the appended claims.

What I claim is:

1. In an apparatus such as described, the combination of a face piece, a rebreather receptacle for exhaled gas, ages-supply conduit entering said receptacle, a gas receptacle of smaller capacity in the first-mentioned receptacle receiving a terminal of said conduit, and valve means interconnecting said face piece and said receptacles whereby the first portion of the user's inhalation is drawn from said gas receptacle and the remaining portion is drawn from the rebreather receptacle.

2. In an apparatus such as described, the combination of a face piece, a rebreather receptacle for exhaled gas, a gas-supply conduit. entering said receptacle, a gas receptacle of smaller capacity in the first-mentioned receptacle receiving a terminal of said conduit, and means interconnecting said face piece and said receptacles, and

including at least three check valves by which means the first portion of the users inhalation is drawn from said gas receptacle and the remaining portion is drawn from the rebreather receptacle.

3. In an apparatus such as described, the combination of a face piece having a valve extending through the periphery thereof, a rebreather receptacle for exhaled gas, a gas-supply conduit entering said receptacle, a gas receptacle of smaller capacity in the first-mentioned receptacle receiving a terminal of said conduit, and means interconnecting said face piece and said receptacles and including at least three check valves by which means the first portion of the users inhalation is drawn from said gas receptacle and a subsequent portion is drawn from the rebreather receptacle.

4. In an apparatus such as described, the combination of a face piece, a rebreather receptacle for exhaled gas, a gas-supply conduit entering said receptacle, a gas receptacle of smaller capacity in the first-mentioned receptacle receiving a terminal of said conduit, and means interconnecting said face piece and said receptacles and including at least two inlet valves and one exhaust valve by which means the first portion of the users inhalation is drawn from the said gas receptacle and the remaining portion is drawn from the rebreather receptacle.

5. In an apparatus such as described, the combination of a face piece having an exhaust valve therein, for exhausting to the atmosphere the last portion of an exhalation, a rebreather receptacle for exhaled gas of a capacity sufficient to hold only the first portion of an exhalation, a gas-supply conduit entering said receptacle, a gas receptacle of smaller capacity in the first-mentioned receptacle receiving a terminal of said conduit, and valve means connecting said face piece and said receptacles whereby the first portion of the users inhalation is drawn from said gas receptacle and a subsequent portion is drawn from the rebreather receptacle.

6. In an apparatus such as described, the combination of a face piece having a body part provided with an exhaust valve and having a tubular part depending therefrom, a flexible rebreather bag penetrated by said tubular part, a gas-supply conduit penetrating the 'rebreather bag and having a terminal portion thereof extending into the lower end of said tubular part, an inlet check valve closing the tubular part intermediate the ends thereof, the portion of said tubular part extending below said inlet valve forming a gas receptacle, a second inlet check valve, said second inlet valve being disposed in the wall structure of the tubular part and opening into said portion thereof, and an outlet check valve opening into said bag and provided in the wall structure of said tubular part intermediate the first inlet valve and the upper end of said tubular part.

7. In an apparatus such as described, the combination of a face piece having a body part provided with an exhaust valve and having a depending tubular part, a flexible rebreather bag penetrated by the tubular part, the tubular part being closed by an inlet check valve at the lower end portion thereof, a supplemental bag forming a gas receptacle and penetrated by the lower end portion of said tubular part, and a gas-supply conduit extending into said gas receptacle, said tubular part being provided with inlet and outlet check valves communicating with said rebreather bag and disposed intermediate said inlet valve and the upper end of said tubular part.

8. in an apparatus such as described, the combination of a face piece having an exhaust valve therein for exhausting to the atmosphere the last portion of an exhalation, a rebreather receptacle for exhaled gas of a capacity to hold only the first portion of an exhalation, a gas supply conduit entering said receptacle, means forming a gas receptacle of a smaller capacity in the firstmentioned receptacle receiving .a terminal of said conduit and including an upper extension connecting the same to the face piece, an inlet check valve in said means below the upper end thereof, an outlet check valve in said means above said inlet valve and opening into the first-mentioned receptacle, and a second inlet valve in said means opening into the latter from the first-mentioned receptacle, whereby the first portion of the users inhalation is drawn from said gas receptacle and a subsequent portion is drawn from the rebreather receptacle.

9. In an apparatus such as described, the combination of a face piece having an exhaust valve therein for exhausting to the atmosphere the last portion of an exhalation, a rebreather receptacle for exhaled gas of a capacity to hold only the first portion of an exhalation, a gas supply conduit entering said receptacle, means forming a gas receptacle of a smaller capacity in the firstrnentioned receptacle receiving a terminal of said conduit and including an upper extension connecting the same to the face piece, an inlet check valve in said means below the upper end thereof, an outlet check valve in said means above said inlet valve and opening into the firstmentioned receptacle, and a second inlet valve in said means opening into the latter from the first-mentioned receptacle, whereby the first portion of the users inhalation is drawn from said gas receptacle and a subsequent portion is drawn from the rebreather receptacle, said second inlet valve being disposed below the first inlet valve.

Wiltz Dec.'30, 1941 Koza Sept. 30, 1953 

